Rack apparatus to prevent tipping of a mobile dishwasher

ABSTRACT

This invention relates to a dishwasher cabinet construction to prevent tipping by insuring that only one dish supporting rack may be fully extended at a time. A rack positioning double-crank lever limit bar is pivotally supported on one side wall of the tub at its center and spring-biased in a dead-center position such that cam surfaces on the limit bar upper and lower arms engage cam following actuator members at the rear of the upper and lower racks, respectively, such that the pivoting of the bar in a first direction, for example, prevents outward movement of the upper rack when the lower rack has been moved to its full outward position.

United States Patent. 1191 Jacobs RACK APPARATUS TO PREVENT TIPPING OF A MOBILE DISHWASHER [75] inventor: James W. Jacobs, Dayton, Ohio [73] Assignee: General Motors Corporation,

' Detroit, Mich.

[22] Filed: Dec. 4, 1972 [21] Appl. No.: 311,957

[52] US. Cl 312/273, 312/311, 312/351 [51] Int. Cl A47b 88/02 [58] Field ofSearch ..312/271,3l1,35l,221,

[56] References Cited UNITED STATES PATENTS R26,902 5/1970 llevenberg .j 312/221 1,868,495 7/1932 Einerman 312 273 2,960,964 11/1960 Murphy 1 49/386 x 3,378,321 I 4/1968 Federick 312/221 x FOREIGN PATENTS OR APPLICATIONS 104,875 3/1917 Great Britain 312/273 [4 1 Mar. 26, 1974 9/1961 Italy 312/273 5/1961 Germany 312/273 Primary Examiner--James T. McCall Attorney, Agent, or Firm-Edward. P. Barthel 7 ABSTRACT This invention relates to a dishwasher cabinet construction to prevent tipping by insuring that only one dish supporting rack may be fully extended at a time. A rack positioning double-crank lever limit bar is pivotally supported on one side wall of the tub at its center and spring-biased in a dead-center position such I that cam surfaces on the limit bar upper and lower arms engage cam following actuator members at the rear of the upper and lower racks, respectively, such that the pivoting of the bar in a first direction, for example, prevents outward movement of the upper rack when the lower rack has been moved to its full outward position.

3 Claims, 5 Drawing Figures PATENIEDIARZWH 3.799640 SHEET 1 UF 2 aw Q RACK APPARATUS TO PREVENT TIPPINC OF A MOBILE DISHWASHER This invention relates to mobile dishwasher cabinets and more particularly to a mobile dishwasher rack structure where only one dish supporting rack may be fully extended at a time.

It is conventional in a front loading mobile dishwasher machine to provide a pair of vertically spaced apart racks for supporting articles to be washed within the washing chamber. The prior art has long recognized the problem inherent in a portable type dishwasher which is not rigidly secured to the floor or other struc-. ture. Means must be provided to prevent tipping of the dishwasher particularly in the event that both upper and lower racks are moved outwardly at the same time. Various means have been proposed, including outriggers or retractable stabilizers, which are expensive and result in excessive utilization of floor area when the dishwasher isnot in use. The present invention pro vides a rack structure for use in a front loading dropdoor dishwasher which prevents tipping while at the same time obviating expensive outriggers or retractable stabilizers. i

It is an object of this invention to provide an improved rack system for a mobile front loading dishwasher which insures that both the upper and lower racks cannot befully extended at the same time. t .It is a further object of this invention to provide. a rack structurefor a mobile front loading dishwasher which includes a T-shaped double-crank lever rack positioner limit bar pivotally supported on the tub side wall at its center having spring-biasing means connected at the endo f the T stem while the upper and lower arms of the bar provide cam surfaces which en gagecam-following actuation members on the upper and lower racks respectively in a sliding manner such that pivoting of the limit bar in one direction prevents the outward movement of the upper rack when the lower rack is moved to its full outward position and vice versa. r y

Other features and advantages of the invention will be apparent fromthe followingdescriptionof a certain embodiment taken in combination with the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the Drawings:

FIG. 1 is a generally schematic representation of a dishwasher providing a side elevational view, partially cut away to show details, of an automatic mobile dishwasher employing the present invention with both the racks retracted;

FIG. 2 is a side view of the dishwasher, partially cut away to show details, with the upper rack fully extended; v

FIG. 3 is a view similar to FIG. 2 with the lower rack fully extended; S

FIG. 4 is a sectional view taken along the line 44 of FIG. 1; and

FIG. 5 is an enlarged fragmentary sectional view taken on line 5-5 of FIG. 1 showing the stop hub mounting structure.

In accordance with the invention and with reference to FIG. 1, a mobile dishwasher is shown having an outer cabinet 10 supportedon wheels 11 including-a top 12,

Side panels one of which is partially indicated at l3,a rear panel 14 and a base portion 16 adapted to enclose the dishwashing chamber or tub shown generally at 18. The dishwashing chamber 18 is generally a box-like receptacle having a depressed bottom defining a sump 20, and an access opening 22 in the front wall thereof above the lower front panel 23. Closing the opening is a pull-down dishwasher door shown generally at 24, which maybe hinged and latched to the side panels of the dishwasher in any conventional manner for pulldown opening by the handle 26 as shown in US Pat. 2,734,520 issued to Abresch et al. on Feb. 14, 1956, and assigned to the assignee of the present application, disclosure of which is incorporated by reference herein.

As seen inFIG. 1, there is provided an upper rack 30 and a lower rack 32 with-the upper rack mounted upon a drawer type guide system 34 such as shown in the Abresch'patent. As disclosed in the Abresch patent, these guides include a J-shaped guide 35 fastened to the rack 30, roller 36of plastic material such as nylon which rolls in the upper guide 35 but whose axes is connected to the lower guide 37. The C-shaped lower guide 37 has slots 38 receiving a pair of spaced rollers 39 which are fastened to the side walls of the dishwashing tub 18.

The lower. rack is provided with two sets of two flanged wheels 42, 44 of a plastic material on either side arranged as shown in FIG. 1. These are arranged to roll on tracks 46 fastened to the opposite side walls of the tub!!! of the dishwashing machine. The door 24 has an enlarged bead 48 which is provided in the inner sheet metal portion of the door on the top and sides thereof. This enlarged bead when the door is in the open position aligns itself with'the tracks 46 provided upon the side walls of the tub. The flanged wheels are spaced far enough so that one of each pair of wheels will be in contact with either the track 46 or the enlarged bead 48 as the set of wheels cross the gap between the track and the enlarged head. This arrangement makes. it possible for both the upper and lower racks to be pulled out all the way so that they can be easily and rapidly filled with articles to be washed and v which can be. readily. and rapidly removed after the washing is completed. Fora more detailed explanation of a similar type of slide-out arrangementfreference may be hadto the above-mentioned Abresch patent, it being understood that the particular slide-out mechanism disclosed is not critical to the present invention."

As seen in FIG. 4, a T-shaped lever means 50 is pivotally mounted to the tub right side wall 52 and includes a horizontally arrangedaxle or pivot pin 54, which is rotatably journaled in a bearing 56 that is suitably mounted in an opening 58 on the tub right side wall 52 at a point substantially midway between the tub back wall 60 and the access opening 22 and is horizontally disposed intermediate the upper and lower racks.

The T-shaped lever means 50 includes a cross-arm limit bar with the stem portion 62of the T in the form of a spring arm oriented at right angles to the collinear upper lever arm'64 and the lower lever arm 66 comprising the cross-arm limit bar. As best seen in FIG. 4, the axle 54 has an inner end that extends within the tub with the upper 64 and lower 66 lever arms secured to the inner end of the axle 54 for pivotal movement therewith while they stem arm 62 is secured to the outer end of the axle 54 for pivotal movement therewith out- The upper and lower lever arms of the limit bar are biased in a vertical position as disclosed in FIG. 1 by yieldable means comprising a tension spring 68 connected between the free end of the T stem portion 62 and peg means 69 on the outer face of the side wall 52 of the tub. The spring 68 biases the double-crank lever a location shown in dashed lines in FIG. 1. As the upper rack is pulled out to its fully extended position shown in FIG. 2, the cam following hub 74 slidably engages with and moves'along the cam surface 72 causing pivotal movement of the lever means 50 about the axle 54 in a first direction (counterclockwise as seen in FIG. 2) opposite to that urged by the spring 68.

Assimilarly seen in FIG. 1, the lowerlever arm 66 of the cross-arm. is provided'w-ith a cam surface 76 which is adapted to engage a cam following actuator member or stop hub 78 mounted on the aft portion of the lower rack 32 upon the lower rack being pulled out approximately half-way from the tub to a location shown in dashed lines in FIG. 1. As the lower rack 32 is pulled out to its fully extended position shown in FIG. 3 the cam following hub 78 slidably engages with and moves along the cam surface 76 causing pivotal movement of the limit bar 50 about the axle 54 in a second direction (clockwise as seen in FIG. 3) opposite to that urged by the spring 68.

It will be appreciated that in the operation shown in FIG. 2 that upon the upper rack being fully extended the cam surface 76 of the lower arm will engage the lower rack cam following hub 78 in such a manner to prevent a loaded lower rack 32 from being pulled out at thesame time unto the door which could result in the forward tipping of the dishwasher. In a similar manner in the case of FIG. 3 upon the lower rack being fully extended unto the door 24 the cam surface 72 of the upper arm will engage the upper rack cam following hub 74 in such a manner to prevent a loaded upper rack 30 from being pulled out at the same time which could again result in the forward tipping of the dishwasher.

It should be noted that the spring 68 is designed with a tension force that is sufficient to return bias or rotate the limit bar 50 into its neutral position (FIG. 1) upon either the upper or lower rack being fully returned to its aft position within the tub by the operator. The spring tension, however, is insufficient to cause either of the racks to automatically return into the tub even when empty until the operator pushes in on the extended rack. It will also be appreciated that both the upper and lower racks may be partially extended at the same time to their dashed line position shown in FIG. 1.

As seen in FIG. 5 for the upper rack 30 the stop hub 74 has a horizontally arranged shaft portion 82 rotatably mounted in the upper end of a leaf spring member 84 while the lower end of the leaf spring 84 is suitably affixed to the longitudinal lower rack wire 86. The

upper end of the leaf spring 84 is U-shaped to provide a clip portion 88 which is adapted to snap over the longitudinal upper rack wire 90 to retain the leaf spring in its solid line position. Thus, when it is desired to remove the upper rack 30 the leaf spring clip 88 may be unsnapped and flexed outwardly to its dashed line position allowing the hub 74 to clear the upper cam surface 72 after which the upper rack 30 may be completely removed from the dishwasher. In an identical manner a leaf spring 94 is used to mount the stop hub 78 on the lower rack 32 to allow the lower rack to be completely removed from the dishwasher.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

I claim:

1. An appliance comprising; a free standing cabinet structure forming an enclosure having an access opening formed at the front thereof; a closure member for said access opening pivotable about its lower edge between a substantially vertical closing position and a substantially horizontal open position; upper and lower racks each having two sides, a front and a back forming a substantially horizontal rectangle, said first and second racks respectively mounted at upper and lower levels of said enclosure; upper and lower mounting means respectively mounting said racks for horizontal sliding movement, each of said racks being movable between a first retracted position in which it is fully within said enclosure and a second position in which a major portion of the rack is extended out through said access opening over said closure member in its open position; a T-shaped lever including a cross arm limit bar pivotally mounted'at the junction of its stem arm, said cross arm limit bar including upper and lower lever arms, yieldable means connected between the cabinet structure and the free end of said stem arm for yieldably urging said limit bar cross arm into a dead-center position wherein the upper and lower lever arms are normally biased in vertically oriented positions, cam following actuator members mounted on a common side of each of the racks adjacent the back thereof, each of said upper and lower lever arms having its rearward facing edge providing a cam surface which is adapted to be engaged by respective ones of said upper and lower rack cam-following actuator members upon its associated rack being extended part-way out from its inward first retracted position, the partially extended rack upon being moved to its second extended position resulting in the sliding of its cam following actuator member along its associated lever arm cam surface, whereby said T-shaped lever pivots in a first direction causing the cam surface on the opposite lever arm to engage its associated cam following actuator member to maintain the otherremaining rack in its first retracted position, and vice versa upon the movement of the other rack such that only one of the racks may be fully extended at any one time to obviate tipping of said appliance. I

2. A dish washing machine comprising; a freestanding cabinet structure forming a box-like tub having an access opening formed at the front thereof; a closure member for said access opening pivotable about its lower edge between a substantially vertical 1 closed position and a substantially horizontal open position; upper and lower wire dish racks each having two sides, a front and a back forming a substantially horizontal rectangle, said upper and lower racks respectively mounted at upper and lower levels of said tub and formed to provide dish receiving compartments at said levels; upper and lower mounting means respectively mounting said upper and lower racks for horizontal sliding movement, each of said dish racks being movable between a first position in which it is fully within said tub and a second position in which a major portion of the rack is extended out through said access opening over said closure member in its open position; the improvement wherein an axle rotatably journaled in a side wall of the tub and having an inner end inside the tub and an outer end outside the tub, a T-shaped lever including a cross arm limit bar having the intermediate portion thereof mounted on the inner end of and lower racks adjacent the back thereof, each of said upper and lower lever arms having its rearward facing edge providing a cam surface which is adapted to be engaged by respective ones of said upper and lower cam-followingactuator members upon its associated upper or lower rack being extended approximately half-way out from its inward first position, the one partially extended rack upon being moved to its second extended position resulting in the sliding of its cam following actuator member along its associated lever arm cam surface, whereby said T-shaped lever means pivots in a first direction causing the distal portion of the cam 'surface on the opposite lever arm to engage its associated cam following actuator member to hold the other remaining rack in its fully retracted position, said spring means operative to return said T-shaped lever means to its dead-center position upon the one extended rack being moved back to its first position, and

, vice versa upon movement of the other rack such that only one of the racks may be fully extended at any one time to obviate tipping of said dish washing machine.

3. The appliance defined in claim 1 wherein said racks are wire dish racks, each of said cam following actuator members being in the form of hub members mounted on one end of a vertically oriented leaf spring, the leaf spring having said one end U-shaped to provide clip means adapted to engage a longitudinal wire of its associated rack side in a snap-like manner, whereby said leaf spring one end may be readily unsnapped from the rack longitudinal wire and flexed in a transverse direction thereto allowing said hub to clear its associated lever arm cam surface such that the rack may be completely removed from the appliance. 

1. An appliance comprising; a free standing cabinet structure forming an enclosure having an access opening formed at the front thereof; a closure member for said access opening pivotable about its lower edge between a substantially vertical closing position and a substantially horizontal open position; upper and lower racks each having two sides, a front and a back forming a substantially horizontal rectangle, said first and second racks respectively mounted at upper and lower levels of said enclosure; upper and lower mounting means respectively mounting said racks for horizontal sliding movement, each of said racks being movable between a first retracted position in which it is fully within said enclosure and a second position in which a major portion of the rack is extended out through said access opening over said closure member in its open position; a T-shaped lever including a cross arm limit bar pivotally mounted at the junction of its stem arm, said cross arm limit bar including upper and lower lever arms, yieldable means connected between the cabinet structure and the free end of said stem arm for yieldably urging said limit bar cross arm into a dead-center position wherein the upper and lower lever arms are normally biased in vertically oriented positions, cam following actuator members mounted on a common side of each of the racks adjacent the back thereof, each of said upper and lower lever arms having its rearward facing edge providing a cam surface which is adapted to be engaged by respective ones of said upper and lower rack cam-following actuator members upon its associated rack being extended part-way out from its inward first retracted position, the partially extended rack upon being moved to its second extended position resulting in the sliding of its cam following actuator member along its associated lever arm cam surface, whereby said T-shaped lever pivots in a first direction causing the cam surface on the opposite lever arm to engage its associated cam following actuator member to maintain the other remaining rack in its first retracted position, and vice versa upon the movement of the other rack such that only one of the racks may be fully extended at any one time to obviate tipping of said appliance.
 2. A dish washing machine comprising; a free-standing cabinet structure forming a box-like tub having an access opening formed at the front thereof; a closure member for said access opening pivotable about its lower edge between a substantially vertical closed position and a substantially horizontal open position; upper and lower wire dish racks each having two sides, a front and a back forming a substantially horizontal rectangle, said upper and lower racks respectively mounted at upper and lower levels of said tub and formed to provide dish receiving compartments at said levels; upper and lower mounting means respectively mounting said upper and lower racks for horizontal sliding movement, each of said dish racks being movable between a first position in which it is fully within said tub and a second position in which a major portion of the rack is extended out through said access opening over said closure member in its open position; the improvement wherein an axle rotatably journaled in a side wall of the tub and having an inner end inside the tub and an outer end outside the tub, a T-shaped lever including a cross arm limit bar having the intermediate portion thereof mounted on the inner end of said axle for movement therewith; said T-shaped lever having a stem arm mounted with one of its opposite ends on the outer end of said axle for movement therewith, spring means connected between the cabinet structure and the other free end of said stem arm for yieldably urging said cross arm limit bar into a dead-center position wherein the upper and lower lever arms of said cross arm limit bar are normally biased in vertically oriented positions, a cam following actuator member mounted on a common side of each of the upper and lower racks adjacent the back thereof, each of said upper and lower lever arms having its rearward facing edge providing a cam surface which is adapted to be engaged by respective ones of said upper and lower cam-following actuator members upon its associated upper or lower rack being extended approximately half-way out from its inward first position, the one partially extended rack upon being moved to its second extended position resulting in the sliding of its cam following actuator member along its associated lever arm cam surface, whereby said T-shaped lever means pivots in a first direction causing the distal portion of the cam surface on the opposite lever arm to engage its associated cam following actuator member to hold the other remaining rack in its fully retracted position, said spring means operative to return said T-shaped lever means to its dead-center position upon the one extended rack being moved back to its first position, and vice versa upon movement of the other rack such that only one of the racks may be fully extended at any one time to obviate tipping of said dish washing machine.
 3. The appliance defined in claim 1 wherein said racks are wire dish racks, each of said cam following actuator members being in the form of hub members mounted on one end of a vertically oriented leaf spring, the leaf spring having said one end U-shaped to provide clip means adapted to engage a longitudinal wire of its associated rack side in a snap-like manner, whereby said leaf spring one end may be readily unsnapped from the rack longitudinal wire and flexed in a transverse direction thereto allowing said hub to clear its associated lever arm cam surface such that the rack may be completely removed from the appliance. 